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      1 /*
      2  * Copyright 2014 The Android Open Source Project
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #include "SkMatrixImageFilter.h"
      9 #include "SkBitmap.h"
     10 #include "SkCanvas.h"
     11 #include "SkDevice.h"
     12 #include "SkColorPriv.h"
     13 #include "SkReadBuffer.h"
     14 #include "SkWriteBuffer.h"
     15 #include "SkMatrix.h"
     16 #include "SkRect.h"
     17 
     18 SkMatrixImageFilter::SkMatrixImageFilter(const SkMatrix& transform,
     19                                          SkPaint::FilterLevel filterLevel,
     20                                          SkImageFilter* input)
     21   : INHERITED(input),
     22     fTransform(transform),
     23     fFilterLevel(filterLevel) {
     24 }
     25 
     26 SkMatrixImageFilter* SkMatrixImageFilter::Create(const SkMatrix& transform,
     27                                                  SkPaint::FilterLevel filterLevel,
     28                                                  SkImageFilter* input) {
     29     return SkNEW_ARGS(SkMatrixImageFilter, (transform, filterLevel, input));
     30 }
     31 
     32 SkMatrixImageFilter::SkMatrixImageFilter(SkReadBuffer& buffer)
     33   : INHERITED(1, buffer) {
     34     buffer.readMatrix(&fTransform);
     35     fFilterLevel = static_cast<SkPaint::FilterLevel>(buffer.readInt());
     36 }
     37 
     38 void SkMatrixImageFilter::flatten(SkWriteBuffer& buffer) const {
     39     this->INHERITED::flatten(buffer);
     40     buffer.writeMatrix(fTransform);
     41     buffer.writeInt(fFilterLevel);
     42 }
     43 
     44 SkMatrixImageFilter::~SkMatrixImageFilter() {
     45 }
     46 
     47 bool SkMatrixImageFilter::onFilterImage(Proxy* proxy,
     48                                         const SkBitmap& source,
     49                                         const Context& ctx,
     50                                         SkBitmap* result,
     51                                         SkIPoint* offset) const {
     52     SkBitmap src = source;
     53     SkIPoint srcOffset = SkIPoint::Make(0, 0);
     54     if (getInput(0) && !getInput(0)->filterImage(proxy, source, ctx, &src, &srcOffset)) {
     55         return false;
     56     }
     57 
     58     SkRect dstRect;
     59     SkIRect srcBounds, dstBounds;
     60     src.getBounds(&srcBounds);
     61     srcBounds.offset(srcOffset);
     62     SkRect srcRect = SkRect::Make(srcBounds);
     63     SkMatrix matrix;
     64     if (!ctx.ctm().invert(&matrix)) {
     65         return false;
     66     }
     67     matrix.postConcat(fTransform);
     68     matrix.postConcat(ctx.ctm());
     69     matrix.mapRect(&dstRect, srcRect);
     70     dstRect.roundOut(&dstBounds);
     71 
     72     SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(dstBounds.width(), dstBounds.height()));
     73     if (NULL == device.get()) {
     74         return false;
     75     }
     76 
     77     SkCanvas canvas(device.get());
     78     canvas.translate(-SkIntToScalar(dstBounds.x()), -SkIntToScalar(dstBounds.y()));
     79     canvas.concat(matrix);
     80     SkPaint paint;
     81 
     82     paint.setXfermodeMode(SkXfermode::kSrc_Mode);
     83     paint.setFilterLevel(fFilterLevel);
     84     canvas.drawBitmap(src, srcRect.x(), srcRect.y(), &paint);
     85 
     86     *result = device.get()->accessBitmap(false);
     87     offset->fX = dstBounds.fLeft;
     88     offset->fY = dstBounds.fTop;
     89     return true;
     90 }
     91 
     92 void SkMatrixImageFilter::computeFastBounds(const SkRect& src, SkRect* dst) const {
     93     SkRect bounds = src;
     94     if (getInput(0)) {
     95         getInput(0)->computeFastBounds(src, &bounds);
     96     }
     97     SkMatrix matrix;
     98     matrix.setTranslate(-bounds.x(), -bounds.y());
     99     matrix.postConcat(fTransform);
    100     matrix.postTranslate(bounds.x(), bounds.y());
    101     matrix.mapRect(dst, bounds);
    102 }
    103 
    104 bool SkMatrixImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
    105                                          SkIRect* dst) const {
    106     SkMatrix transformInverse;
    107     if (!fTransform.invert(&transformInverse)) {
    108         return false;
    109     }
    110     SkMatrix matrix;
    111     if (!ctm.invert(&matrix)) {
    112         return false;
    113     }
    114     matrix.postConcat(transformInverse);
    115     matrix.postConcat(ctm);
    116     SkRect floatBounds;
    117     matrix.mapRect(&floatBounds, SkRect::Make(src));
    118     SkIRect bounds;
    119     floatBounds.roundOut(&bounds);
    120     if (getInput(0) && !getInput(0)->filterBounds(bounds, ctm, &bounds)) {
    121         return false;
    122     }
    123 
    124     *dst = bounds;
    125     return true;
    126 }
    127